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Best Free UK Investment Tax Calculators 2026 — Capital Gains, Dividends, Inheritance Tax and Child Benefit

Updated for the 2025/26 tax year • All calculators free • No signup required

TL;DR

For UK investment taxes in 2026, the key calculators cover capital gains tax (shares, property, crypto), dividend tax, and inheritance tax. Boring Math's Capital Gains Tax Calculator applies the current annual exempt amount and correct rates for your tax band. For parents earning over £60,000, the Child Benefit Calculator shows the HICBC clawback and whether claiming is still worthwhile. Salary sacrifice can reduce adjusted net income below key thresholds. All calculators are free with no signup.

Top 5 UK Investment Tax Calculators for 2025/26

#1

UK Capital Gains Tax Calculator

Calculates CGT on the sale of assets including shares, property, and crypto, with the annual exempt amount and different rates for basic and higher rate taxpayers.

Best for: Anyone selling investments, second properties, or crypto in the UK.

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#2

UK Dividend Tax Calculator

Calculates tax on dividend income above the dividend allowance, with separate rates for basic, higher, and additional rate taxpayers.

Best for: Company directors, investors, and anyone receiving dividend income.

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#3

UK Inheritance Tax Calculator

Estimates IHT liability on an estate including the nil-rate band (£325,000), residence nil-rate band (£175,000), and spousal exemptions.

Best for: Anyone planning their estate or executors estimating IHT.

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#4

UK Child Benefit Calculator

Calculates the High Income Child Benefit Charge (HICBC) that claws back child benefit when one parent earns over £60,000, plus whether it's worth claiming.

Best for: Parents earning between £60,000 and £80,000 wanting to know if they should claim child benefit.

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#5

UK Salary Sacrifice Calculator

Calculates how much income tax and National Insurance you save by diverting salary into pension, and how this can reduce your adjusted net income below key thresholds (£100k personal allowance taper, £60k HICBC).

Best for: Higher earners using salary sacrifice to reduce tax and retain benefits like child benefit.

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Quick Comparison

Calculator Best for Free No account needed Updated 2025/26
UK Capital Gains Tax Calculator Anyone selling investments, second properties, or crypto in the UK Yes Yes Yes
UK Dividend Tax Calculator Company directors, investors, and anyone receiving dividend income Yes Yes Yes
UK Inheritance Tax Calculator Anyone planning their estate or executors estimating IHT Yes Yes Yes
UK Child Benefit Calculator Parents earning between £60,000 and £80,000 wanting to know if they should claim child benefit Yes Yes Yes
UK Salary Sacrifice Calculator Higher earners using salary sacrifice to reduce tax and retain benefits like child benefit Yes Yes Yes

How to Choose

  • If you're selling shares, a second property, or crypto, use the Capital Gains Tax Calculator to see your CGT liability after the annual exempt amount.
  • If you receive dividends from a company or investments, the Dividend Tax Calculator shows your tax at the correct rate for your band.
  • If you're a parent earning over £60,000, start with the Child Benefit Calculator to see if claiming is still worthwhile after the HICBC clawback.
  • If you're a higher earner looking to reduce your tax bill, the Salary Sacrifice Calculator shows how pension contributions can bring you below key thresholds.

Frequently Asked Questions

How much capital gains tax do I pay in the UK?

In 2025/26, CGT rates are 18% for basic rate taxpayers and 24% for higher and additional rate taxpayers on most assets. Residential property that is not your main home is taxed at 24% for higher rate taxpayers. You get an annual exempt amount of £3,000, so you only pay CGT on gains above that threshold.

How is dividend tax calculated in the UK?

Dividend income above the £500 dividend allowance is taxed at 8.75% for basic rate taxpayers, 33.75% for higher rate taxpayers, and 39.35% for additional rate taxpayers. Dividends use up your tax bands but are taxed at these separate rates rather than income tax rates.

What is the inheritance tax threshold in the UK?

The nil-rate band is £325,000 per person. If you leave your home to direct descendants, the residence nil-rate band adds another £175,000, giving a total threshold of £500,000. Married couples and civil partners can transfer unused allowances, potentially sheltering up to £1,000,000 from IHT.

What is the High Income Child Benefit Charge?

The HICBC is a tax charge that claws back child benefit when the higher-earning parent has adjusted net income over £60,000. Between £60,000 and £80,000, you lose 1% of the benefit for every £200 of income above £60,000. Above £80,000, the full benefit is clawed back. You can still claim child benefit for National Insurance credits even if the charge applies.

Can salary sacrifice help me keep child benefit?

Yes. Salary sacrifice into pension reduces your adjusted net income. If your salary is above £60,000 but you sacrifice enough to bring your adjusted net income below £60,000, the HICBC no longer applies and you keep the full child benefit. This is one of the most effective uses of salary sacrifice for parents.

Do I pay CGT on crypto in the UK?

Yes. HMRC treats cryptocurrency as a taxable asset. When you sell, swap, or spend crypto at a profit, you pay capital gains tax on the gain above your annual exempt amount. The same CGT rates apply as for other assets: 18% for basic rate and 24% for higher rate taxpayers in 2025/26.

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